| 摘要 |
A novel Phillips catalyst for the homopolymerization of ethylene and the copolymerization of ethylene with alpha -olefins contains as catalytically active components a specific chromium catalyst on an aluminum phosphate support and cocatalysts of the formula I to IV, MR (I) M1R2 (II) M2R3-n1Xn (III) MM2RR31 (IV) where M is lithium, sodium and potassium, M1 is magnesium and zinc, M2 is boron and aluminum, R is C1-C10-alkyl and C6-C20-aryl, R1 is R and C1-C10-alkoxy and C6-C20-aryloxy, X is chlorine, bromine and iodine, n is 0, 1 and 2 The chromium catalyst on an aluminum phosphate support can be obtained by applying chromium compounds to a finely divided aluminum phosphate with a P:A1 molar ratio near to or equal to 1 and a pore volume of >1 cm3/g and activating the resulting intermediate at elevated temperatures in an oxidizing atmosphere. The novel Phillips catalyst has an exceptionally long duration of activity and its productivity can be increased further by adding hydrogen. |
